The S&P 500 slipped 0.51% to 1,785.11 in afternoon trading Friday.
The Dow Jones Industrial Average was off 0.76% to 15,728.64, while the Nasdaq was down 0.39% to 4,106.98.
The yield on a 10-year Treasury bond fell 1.08% to 2.66%.
The price of gold was down 0.21% to $1,239.90 per ounce.
Irvine-based CorVel Corp. was down about 3% to $47.10 for a market value of $990.23 million. CorVel provides workers' compensation software and services to the healthcare industry along with others. It reported gains in December quarter revenue and earnings this week.
Irvine-based networking equipment maker Lantronix Inc. was down about 12% to $2.49 for a market value of $36.3 million. The company this week reported December quarter revenue in line with analyst estimates and better-than-expected earnings for its December quarter.